Audible Ringer with Headphones??

WHY does my Note5 ring audibly when I have my HEADPHONES plugged in? I was under the assumption that if I plug my headphones in, then it should NOT ring audibly to the rest of the world, only through my headset/headphones.

What's the deal? How can I make this stop? I have combed the settings and am not finding anything to change this.

Noticed the same earlier this week. Had headphones plugged in and could hear the ringtone playing after removing the headphones from my ears. I'm not aware of a setting that can fix this. Maybe someone will have some ideas.